Phthalocyanine crystal, process for manufacture thereof and its use for electrophotographic photosensitive material

Abstract

A new crystal form of a titanyl phthalocyanine compound is provided. This crystal form shows characteristic strong absorption peaks at 1,332±2 cm -1 , 1,074±2 cm -1 , 962±2 cm -1 and 783±2 cm -1 in an infrared absorption spectrum and/or characteristic strong peaks at 27.2°, 9.7° and 24.1° of Bragg's angle 2θ in an X-ray diffraction spectrum and has very good dispersibility and stability in a solvent and also very good photoelectric conversion efficiency and so is very useful particularly as a charge generation agent highly sensitive in a semiconductor laser wavelength region as required in a photosensitive material for a highspeed high-definition printer. Such crystal form can be obtained by treating non-crystalline titanyl phthalocyanine with tetrahydrofuran.

We claim: 
     
       1. A phthalocyanine crystal which is represented by the general formula: ##STR3## wherein X 1 , X 2 , X 3  and X 4  each independently represent various halogen atoms and n, m, l and k represent numerals of 0 to 4 and shows, in an infrared absorption spectrum, characteristic strong absorption peaks at 1,332±2 cm -1 , 1,074±2 cm -1 , 962±2 cm -1  and 783±2 cm -1 . 
     
     
       2. The phthalocyanine crystal according to claim 1 which shows, in an X-ray diffraction spectrum, the maximum diffraction peak at 27.2° of Bragg's angle (2θ±0.2°) and strong diffraction peaks at 9.7° and 24.1°. 
     
     
       3. A process for the manufacture of a phthalocyanine crystal which shows, in an infrared absorption spectrum, characteristic strong peaks at 1,332±2 cm -1 , 1,074±2 cm -1 , 962±2 cm -1  and 783±2 cm -1 , characterized in that a non-crystalline titanyl phthalocyanine compound is treated with tetrahydrofuran. 
     
     
       4. A phthalocyanine crystal which is represented by the general formula: ##STR4## wherein X 1 , X 2 , X 3  and X 4  each independently represent various halogen atoms and n, m, l and k represent numerals of 0 to 4 and shows, in an X-ray diffraction using Cu-Kα ray, the maximum peak at 27.2° of Bragg's angle (2θ±0.2°) and strong peaks at 9.7° and 24.1°. 
     
     
       5. A process for the manufacture of a phthalocyanine crystal which shows, in an X-ray diffraction spectrum, the maximum diffraction peak at 27.2° of Bragg's angle (2θ±0.2°) and strong diffraction peaks at 9.7° and 24.1°, characterized in that a non-crystalline titanyl phthalocyanine compound is treated with tetrahydrofuran.